Frequently Asked Questions About Linux / UNIX » Backup

Linux / UNIX: Encrypt Backup Tape Using Tar & OpenSSL

nixCraft — Thu, 25 Mar 2010 18:03:12 +0000

How do I make sure only authorized person access my backups stored on the tape drives (DAT, DLT, LTO-4 etc) under Linux or UNIX operating systems? How do I backup /array22/vol4/home/ to /dev/rmt/5mn or /dev/st0 in encrypted mode?

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Rsnapshot WARNING: Could not lchown() symlink "/path/to/file" Error and Solution

nixCraft — Tue, 03 Nov 2009 16:17:05 +0000

I got rsnapshot based backup server up and running for my network under Debian Linux 5.x. But, whenever I run a backup job using the following command:
rsnapshot -v -c /root/rsnapshot.server1.conf hourly
I get the following messages on screen:

WARNING: Could not lchown() symlink "/nas/.rsnapshot/hourly.1/server1.example.com/etc/alternatives/locate" WARNING: Could not lchown() symlink "/nas/.rsnapshot/hourly.1/server1.example.com/etc/alternatives/nc.1.gz" WARNING: Could not lchown() symlink "/nas/.rsnapshot/hourly.1/server1.example.com/etc/alternatives/jexec-binfmt" WARNING: Could not lchown() symlink "/nas/.rsnapshot/hourly.1/server1.example.com/etc/alternatives/servertool"

How do I fix this problem?

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UNIX / Linux Dump Command Exclude Directories / Files

nixCraft — Thu, 11 Jun 2009 12:49:14 +0000

I'm using dump command to backup file systems to tape and remote server. However, I'm not able to find any option that will allow me to exclude files or directories from backup. How do I force UNIX / Linux / FreeBSD dump command to exclude selected files (such as /var/cache or /usr/basejails) which I don't want to backup?

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keychain: Set Up Secure Passwordless SSH Access For Backup Scripts

nixCraft — Sat, 06 Jun 2009 08:08:47 +0000

We establish connections to remote systems without supplying a password, however I do not want to store my password less keys ( passphrase-free keys) on my servers. ssh-agent, takes care of keys with passphase, which allowing me to easily have ssh-agent process per system per login session. How do I dramatically reduces the number of times I've to punch my passphrase from once per new login session to once every time my local server is rebooted? How do I use keychain utility for all my backup scripts for secure passwordless login?

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Freebsd Mount a NAS via SMB / CIFS

nixCraft — Sun, 25 Jan 2009 00:48:22 +0000

Q. I want to use our NAS server to store backups. Our NAS supports FTP and CIFS / SMB sharing technology. How do I mount and store files on NAS using FreeBSD? How do I automate entire procedure using a shell script? Is that doable? If so, what's the easiest solution ftp or CIFS?

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Tar Extract a Single File(s) From a Large Tarball

nixCraft — Fri, 05 Dec 2008 19:02:41 +0000

Q. I've couple of large tarballs such as www.tar and images.tar. Is it possible to extract a single file or a list of files from a large tarball such as images.tar instead of extracting the entire tarball? How do I extract specific files under Linux / UNIX operating systems?

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Thunderbird Move Mail / Settings From Desktop Computer To Laptop

nixCraft — Fri, 12 Sep 2008 21:23:39 +0000

Q. How do I move my Thunderbird email client settings from Debian Linux desktop to a new Ubuntu Linux laptop? I've installed Thunderbird on Ubuntu Linux but not able to find any import or export option. How do I move settings?

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How To Back Up a Web Server

nixCraft — Sat, 02 Aug 2008 11:25:19 +0000

Q. I'm using Red Hat Enterprise Linux based Apache web server. How do I backup my Apache webserver, MySQL and PostgreSQL database to another disk called /backup and then copy it to other offsite backup ssh server called backup.example.com?

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How To Set Red hat / CentOS Linux Remote Backup / Snapshot Server

nixCraft — Sat, 05 Jul 2008 19:12:15 +0000

I've HP RAID 6 server running RHEL 5.x. I'd like to act this box as a backup server for my other Red Hat DNS and Web server. The server must keep backup in hourly, daily and monthly format. How do I configure my Red Hat / CentOS Linux server as remote backup or snapshot server?

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FreeBSD cvsup: Update The FreeBSD From Previous Releases Using Source Code

nixCraft — Tue, 24 Jun 2008 17:38:03 +0000

How do I update my system using cvsup mirror? How do I upgrade from previous releases using FreeBSD 6.x or 7.x? How do I upgrade everything including kernel, userland utilities, and installed applications?

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Linux tar: /dev/st0: Cannot write: Invalid argument error and solution

nixCraft — Thu, 05 Jun 2008 13:13:05 +0000

Q. When I run tar command it fails with an error that read as follows: tar: /dev/st0: Cannot write: Invalid argument How do I fix this error under CentOS / Debian / Fedora / RHEL Linux HP server systems? A. You need to specify the block factor size. If you try to write a large [...]

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Can RAID Act As The Reliable BACKUP Solution For Linux / UNIX / Windows Server?

nixCraft — Sun, 01 Jun 2008 13:13:16 +0000

Can I use RAID as the only backup solution under Linux? Is RAID is reliable backup solution for server?

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Linux LVM error VG meta data inconsistent and Solution

nixCraft — Tue, 13 May 2008 13:13:18 +0000

Q. How do I fix the following error under CentOS Enterprise Linux:

LVM error VG meta data inconsistent

How do I fix this error?

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How To Use rsync Command To Backup Directory Under Linux

nixCraft — Sun, 02 Mar 2008 20:28:32 +0000

Q. How do I use rsync command to back up a home directory under Linux operating system? A. rsync command easily backup your home directory to local secondary hard disk or remote server using ssh protocol. rsync is a software application for Unix systems which synchronizes files and directories from one location to another while [...]

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Debian / Ubuntu Linux Install and Configure Remote Filesystem Snapshot with rsnapshot Incremental Backup Utility

nixCraft — Mon, 11 Feb 2008 11:33:10 +0000

I'd like to configure my Debian box to backup two remote servers using rsnapshot software. It should make incremental snapshots of local and remote filesystems for any number of machines on 2nd hard disk located at /disk1 ( /dev/sdb2).

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Exclude Certain Files When Creating A Tarball Using Tar Command

nixCraft — Wed, 18 Oct 2006 17:32:15 +0000

How can I keep out certain files when creating a tarball? For example:

/home/me/file1
/home/me/dir1
/home/me/dir2
/home/me/abc
/home/me/xyz

How do I execute zyz and abc file while using a tar command?

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How can I restore a backup of a MySQL database?

nixCraft — Sat, 29 Jul 2006 02:58:00 +0000

Q. I made MySQL backup using mysqldump -u user -h localhost -ppassword forumdb | -gzip -9 > forumdb.sql.gz command. How do I restore MySQL database backup using a shell prompt under Linux / UNIX operating system? A. mysqldump command is text-based client or tool for dumping or backing up mysql databases, tables and or data. [...]

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Linux Tape Backup With mt And tar Command Howto

nixCraft — Wed, 19 Apr 2006 16:46:00 +0000

Magnetic tape is a non-volatile storage medium consisting of a magnetic coating on a thin plastic strip. Nearly all recording tape is of this type, whether used for video, audio storage or general purpose digital data storage using a computer. How do I make backup using tapes under Linux operating systems?

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